Continuous casting dummy bar head casting conveyor

ABSTRACT

An apparatus for driving and guiding a continuous cast strand from an initial position at an open-ended mold to a second position within a withdrawal roll unit. The apparatus comprises external conveyor means which extend from the mold into the withdrawal unit to drive a dummy bar head from the mold through a predetermined path into the withdrawal unit. The dummy bar head acts as the bottom of the mold at cast startup and becomes integral with the cast strand at pouring. The head is driven by pivot pins extending from the head into coupling engagement with the conveyor means and is automatically released from the conveyor when driving of the cast strand is assumed by the withdrawal unit pinch rolls.

United States Patent Lomax [45] Mar. 7, 1972 [54] CONTINUOUS CASTING DUMMY BAR HEAD CASTING CONVEYOR [72] Inventor: Donald L. Lornax, Glen Mills, Pa.

[73] Assignee: Gull & Western Industrial Products Company, Grand Rapids, Mich.

[22] Filed: June 1, 1970 211 Appl. No.: 41,926

[52] U.S.Cl ..164/274, 164/282 [58] Field ofSearch ..l64/82,274, 282, 283

[56] References Cited UNITED STATES PATENTS 3,318,366 5/1967 Foldessy 164/274 3,374,828 3/1968 Menu .164/274 3,446,270 5/1969 Michelson 164/274 X Primary Examiner-R. Spencer Annear Attorney-Meyer, Tilberry and Body [5 7] ABSTRACT An apparatus for driving and guiding a continuous cast strand from an initial position at an open-ended mold to a second position within a withdrawal roll unit. The apparatus comprises external conveyor means which extend trom the mold into the withdrawal unit to drive a dummy bar head from themold through a predetermined path into the withdrawal unit. The dummy bar head acts as the bottom of the mold at cast startup and becomes integral with the cast strand at pouring. The head is driven by pivot pins extending from the head into coupling engagement with the conveyor means and is automatically released from the conveyor when driving of the cast strand is assumed by the withdrawal unit pinch rolls.

1] Claims, 5 Drawing Figures PAIENTEUHAR 1 I912 3,646,989

0 2 (a. 2 INVENTOR.

MAX

ATTORNEYS CONTINUOUS CASTING DUMMY BAR HEAD CASTING CONVEYOR This application pertains to the art of continuous casting and more particularly to the withdrawal of a continuous cast ingot from a continuous casting mold.

The invention is particularly applicable to a continuous casting operation in which a curved vertical, water-cooled, flow-through mold is provided with a temporary bottom in the form of a dummy bar head which is withdrawn slowly during pouring from the tundish into the mold, and will be described with particular reference thereto, although it is appreciated that the invention is capable of broader applications which will be apparent to those skilled in the art.

Heretofore, dummy bars were required to draw the cast strand from the mold through a spray apron and withdrawal unit. These dummy bars were made of steel links fastened together with pivot pins to facilitate negotiating the required curved travel from mold to withdrawal unit. A dummy bar head with the same general cross-sectional configuration as the cross section of the cast strand functioned as a temporary bottom for the mold and was attached to the end dummy bar. This linkage was connected to a power unit in order to pull the strand from the mold. As the dummy bars passed through the withdrawal unit, they had to be disconnected from the continuous cast strand and linkage and stored out of the way for the remainder of the cast. Following each cast, a new dummy bar head was attached to the dummy bar linkage and relocated as the temporary mold bottom in preparation for the next cast. This arrangement resulted in the need for extremely expensive dummy bar equipment. In addition, elaborate storage arrangements for handling the dummy bars as they were removed from the linkage during the cast were necessarily required.

The present invention contemplates a new apparatus which overcomes all of the above-referred disadvantages and others, and provides a withdrawal means which is less technical in nature, more economical, and requires less maintenance attention.

In accordance with the present invention, there is provided a withdrawal means which includes a conveyor means to drive a dummy bar head through adesired cooling path, a dummy bar head which acts as a temporary bottom for the continuous casting mold at the start of the cast, transversely extending pivot pins to allow attachment of the dummy bar head to the conveyor means, and guide and retaining channels to retain the dummy bar head in its position along the conveyor means.

The principal object of the invention is the provision of means for positively driving a dummy bar head from its position as the temporary bottom of a flow-through mold to a position subsequent to the operation of the first withdrawal unit pinch rolls to eliminate the need for conventional dummy bars.

A further object of the invention is the provision of a means for positively driving a dummy bar head from its position as the temporary bottom of a flow-through mold which means decreases setup time and effort in the overall casting operation.

Still a further object of the invention is the provision of a means for powering a dummy bar head from a position as-temporary bottom of a flow-through mold to a position subsequent thereto in which a variety of different sized dummy bar heads may be utilized.

These and other objects will become apparent by referring to the following description and drawings wherein:

FIG. I is a side elevational view of a curved continuous casting installation utilizing the dummy bar head and conveyor;

FIG. 2 is a perspective view of the conveyor embodiment shown in FIG. 1;

FIG. 3 is an enlarged elevational view of a conveyor drive sprocket;

FIG. 4 is a plan view of a dummy bar head in conveyor engagement; and

FIG. 5 is a cross-sectional view of the apparatus shown in FIG. 4 taken along line 5-5.

Referring now to the drawings wherein the figures are for the purpose of illustrating the preferred embodiment of the invention only and not for purposes of limiting same, FIG. I depicts a curved vertical continuous casting device A comprised of a tundishZ, an open-ended water-cooled mold 4, and molten metal 6 which is poured from tundish2 into mold 4. Adjacent to and below casting device A is withdrawal unit B. Withdrawalunit B comprises frame 8, variable speed driving unit 10, upper end sprockets l2 and 14 with connecting shaft 15, lower end sprockets I6 and 18 with connecting shaft I9, guide channels 20 and 22, and conveyor chains 24 and 26 comprised of conveniently interconnected alternating links 28 and 30.

As best shown in FIG. 2, dummy barhead 32 has transverse directional pivot pins 34 and 36 for coupling engagement in chains 24 and 26. Each link 28 of chains 24 and 26 has an open-ended arcuate slot 40 for engagement of dummy bar head pivot pins 34 and 36. Slots 40 are generally U-shaped with nominally larger radii than pivotpins 34 and 36. Engagement of pivot pins 34 and 36 in slots 40 in chains 24 and 26, is best shown in FIGS. 2, 3, 4 and 5. Guide channels 20 and 22 each have a slot 42 running longitudinally along the inside edge. Slots 42 are of sufficient width to receive pivot pins 34 and 36 during engagement with slots 40 in chains 24 and 26.

Referring again to FIGS. 1 and 2, withdrawal unit B is generally shaped identical to the standard attendant equipment C, comprised of spraying units 46 androller apron rollers 48, and to guide channels 20 and 22 and idler rolls 23. Spraying units 46 aid in cooling the cast strand and are located at opposite faces of dummy bar head 32 while roller apron rol- Iers 48 determine the predetermined path of the casting and add support for cast strand during its travel. Located between upper conveyor sprockets l2 and I4 and lower conveyor sprockets l6 and 18 and immediately preceding the lower conveyor sprockets l6and I8 is upper withdrawal roll 50 and lower withdrawal roll 52 which operate in conjunction with a standard withdrawal unit D. The upper withdrawal roll 50 is driven in a clockwise direction and the lower withdrawal roll 52 is driven in a counterclockwise direction. Withdrawal rolls 50 and 52 are conveniently floatingly spring mounted such that dummy bar head 32 may pass between them transverse to their longitudinal axes.

In the operation of withdrawal unit B, dummy bar head 32 is first placed in position on withdrawal unit B with pivot pins 34 and 36 each engaging a slot 40 in chains 24 and 26 at the lower conveyor sprockets l6 and 18. Power unit 10, conveniently connected to directly drive connecting shaft 17, is reversed from its normal direction of operation such that the dummy bar head 32 is directed towards mold 4. Roller apron rollers 48 and guide channels 20 and 22 maintain dummy bar head 32 in position throughout travel to mold 4. At the mold, dummy bar head 32 fits into mold opening 54 and acts as the bottom of the mold. At startup of the cast, molten metal 6 is poured from tundish 2 into mold 4 wherein it makes contact with and becomes bonded to dummy bar head 32. Power unit I0, operating in its normal direction at the desired speed, begins to draw dummy bar head 32 slowly from mold 4 and down the predetermined path determined by roller apron rolls 48 and guide channels 20 and 22 of withdrawal unit B. This path has an initial generally vertical portion E immediately adjacent casting device A and extends curvilinearly to a final generally horizontal position F adjacent position E. Along with dummy bar head 32 is withdrawn a strand 56 (FIG. 4) which is-in the general shape of mold opening 54. Spraying units 46 supply coolant to strand 56-to facilitate accelerated cooling to give it added strength and roller apron rolls 48 support and guide strand 56 along the predetermined curved path to prevent undesirable molten metal breakthrough.

As dummy bar head 32 and strand 56 are driven along their predetermined path, they approach and pass between first upper withdrawal roll 50 and first lower withdrawal roll 52. At this passing, withdrawal rolls 50 and 52 are spring forced towards each other to apply pressure on both sides of strand 56 and assume the driving thereof. Immediately subsequent to this drive change, guide channels and 22 end, such that dummy bar head 32 is no longer confined to the movement of conveyor chains 24 and 26. Dummy bar head 32 is automatically released from the operation of withdrawal unit B as chains 24 and 26 travel around the circumference of lower chain sprockets l6 and 18. This releases pivot pins 34 and 36 from their positions within a slot 40 in chain links 28 and 30. it will be appreciated by those skilled in the art that the release of pivot pins 34 and 36, as hereinabove disclosed, may take place anywhere along the path between vertical end portion E and horizontal end portion F. Upper withdrawal roll 50 and lower withdrawal roll 52 then drive strand 56 into a standard withdrawal unit diagrammatically shown as D for further processing.

Following completion of the cast, dummy bar head 32 may be removed from strand 56 for reuse in the next cast.

It is to be understood that withdrawal unit B may be constructed in such a manner to accommodate various sized strands 56 from continuous casting operation A. This may be accomplished by making frame 4 adjustable so that the distance between upper conveyor sprockets l2 and 14 and lower conveyor sprockets l6 and 18 may be varied or by making frame 4 nonadjustable so at least the widest strand 56 may be run and fitting smaller dummy bar heads 32 to it by using extended pivot pins 34 and 36.

Although the invention has been described with reference to specific embodiments and advantages, variations thereto will be known to those skilled in the art.

Having thus described my invention I claim:

1. In a continuous casting device having a mold with an open end through which a continuous strand of metal is cast and means extending from said open end for guiding said strand along a predetermined curved path having an initial generally vertical portion and a final generally horizontal portion, the improvement comprising:

a rigid dummy bar head having means for fixedly receiving the initial end of said cast continuous strand at said openmg;

means for conveying said head and a strand attached thereto along said predetermined curved path, said conveying means being disposed generally coextensive with and adjacent a lateral edge of said curved path and including an element selectively movable along said curved path for conveying said dummy bar head;

first means for releasably interconnecting said dummy bar head and said element, said interconnecting means being constructed to permit limited relative movement between said dummy bar head and said element; and,

means for disengaging said interconnecting means from its interconnecting relationship at a preselected position along said path whereby said head and a strand connected thereto continues along said path.

2. The improvement as defined in claim 1 wherein said preselected position is adjacent said horizontal portion.

3. The improvement as defined in claim 1 wherein said conveying means further includes guide means for guiding said element and said first means along said curved path coextensive with at least a part of said vertical portion, means for causing said element to drivingly engage said first means at a first position, said disengaging means including means on said conveying means for disengaging said first means from said element at a second position generally vertically below said first position.

4. The improvement as defined in claim 3 wherein said conveying means comprises an endless chain conveyor with said endless chain extending around a first sprocket adjacent said first position and a second sprocket adjacent said second position, said chain conveyor defining at least one elongated curs vilinearpass extending coextensive with said path between said first and second positions, said guide means being disposed adjacent said pass between said first and second positrons.

5. The improvement as defined in claim 4 wherein said element is disposed along said endless chain conveyor and includes a first means for coupling said interconnecting means.

6. The improvement as defined in claim 5 wherein said element comprises a link in said endless conveyor, said first coupling means comprises a recess therein; and, said interconnecting means comprises an outwardly extending protrusion on said dummy bar head, the free end thereof being dimensioned to be received in said recess.

7. The improvement as defined in claim 6 wherein said recess is an open-ended slot.

8. The improvement as defined in claim 4 wherein said conveying means comprises two of said endless chain conveyors transversely spaced apart adjacent both lateral edges of said path, said chain conveyors being simultaneously driven about their first and second sprockets.

9. The improvement as defined in claim 1 including strand I drive means for driving said strand, said drive means being adjacent said disengaging means.

10. The improvement as defined in claim 9 wherein said drive means includes a pair of rolls, one on each side of said path.

11. The improvement as defined in claim 4 wherein said guide means comprises an elongated open-ended generally U- shaped channel disposed with said channel opening toward said path, that portion of said chain conveyor comprising said pass being disposed to pass longitudinally through said channel. 

1. In a continuous casting device having a mold with an open end through which a continuous strand of metal is cast and means extending from said open end for guiding said strand along a predetermined curved path having an initial generally vertical portion and a final generally horizontal portion, the improvement comprising: a rigid dummy bar head having means for fixedly receiving the initial end of said cast continuous strand at said opening; means for conveying said head and a strand attached thereto along said predetermined curved path, said conveying means being disposed generally coextensive with and adjacent a lateral edge of said curved path and including an element selectively movable along said curved path for conveying said dummy bar head; first means for releasably interconnecting said dummy bar head and said element, said interconnecting means being constructed to permit limited relative movement between said dummy bar head and said element; and, means for disengaging said interconnecting means from its interconnecting relationship at a preselected position along said path whereby said head and a strand connected thereto continues along said path.
 2. The improvement as defined in claim 1 wherein said preselected position is adjacent said horizontal portion.
 3. The improvement as defined in claim 1 wherein said conveying means further includes guide means for guiding said element and said first means along said curved path coextensive with at least a part of said vertical portion, means for causing said element to drivingly engage said first means at a first position, said disengaging means including means on said conveying means for disengaging said first means from said element at a second position generally vertically below said first position.
 4. The improvement as defined in claim 3 wherein said conveying means comprises an endless chain conveyor with said endless chain extending around a first sprocket adjacent said first position and a second sprocket adjacent said second position, said chain conveyor defining at least one elongated curvilinear pass extending coextensive with said path between said first and second positions, said guide means being disposed adjacent said pass between said first and second positions.
 5. The improvement as defined in claim 4 wherein said element is disposed along said endless chain conveyor and includes a first means for coupling said interconnecting means.
 6. The improvement as defined in claim 5 wherein said element comprises a link in said endless conveyor, said first coupling means comprises a recess therein; and, said interconnecting means comprises an outwardly extending protrusion on said dummy bar head, the free end thereof being dimensioned to be received in said recess.
 7. The improvement as defined in claim 6 wherein said recess is an open-ended slot.
 8. The improvement as defined in claim 4 wherein said conveying means comprises two of said endless chain conveyors transversely spaced apart adjacent both lateral edges of said path, said chain conveyors being simultaneously driven about their first and second sprockets.
 9. The improvement as defined in claim 1 including strand drive means for driving said strand, said drive means being adjacent said disengaging means.
 10. The improvement as defined in claim 9 wherein said drive means includes a pair of rolls, one on each side of said path.
 11. The improvement as defined in claim 4 wherein said guide means comprises an elongated open-ended generally U-shaped channel disposed with said channel opening toward said path, that portion of said chain conveyor comprising said pass being disposed to pass longitudinally through said channel. 